<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #test01 {
            width: 115px;
            height: 21px;
        }

        #test02 {
            width: 115px;
            height: 21px;
            background-color: grey;
            color: white;
            display: none;
            border: 1px solid gray;
            border-radius: 5px;
        }

        #test01:hover+#test02 {
            display: block;
        }
    </style>
</head>

<body>
    <div>
        <div id="test01">昂，你来晚了哈</div>
        <div id="test02">我是提示文字撒</div>
    </div>
</body>

</html>